I currently run Windows XP Pro SP2 and I am buying a new computer. I still intend to run the same OS on that system, but I might change to Vista 64-bit at some point down the line. My question is this: would I be better off with 4GB of slower speed RAM (800 MHz) or 2GB of faster RAM (1066 MHz)?. I intend to use the PC primarily for documents, internet access and gaming.

Some things to consider:

I gather that a 32-bit OS (i.e. what I'm running now) will only allocate a maximum of 2GB to any one process a ta time, whilst a 64-bit OS can allocate more (in application space).

I further gather that a 32-bit Windows OS only has a maximum of 2GB in kernel space to allocate between all running programs. Can one assume that a 64-bit OS would, again, be able to use more?

Even if my Windows XP can only allocate 2GB of RAM to an application at a time, presumably I could run 2 demanind apps at the same time, with each using 2GB?

Edited April 17, 200818 yr by zulu9812

since you haven't defined how far into the future your move to Vista will be (if ever), I'd recommend you buy the 2GB of faster RAM and take advantage of that now, and then if you do move to Vista x64, you could purchase 2GB more if you feel you need it.

So, you're saying that I would get no noticeable benefit from 4GB of RAM under a 32-bit OS?

My personal choice is to go with more slower ram. I have swapped faster ram for slower ram before and never noticed a difference. I have even tried the Kingston Hyper X “Gaming” ram and when I swapped it for regular ram it seemed to be the same to me. I know it’s faster by looking at the graphs that people put out that have tested it but I couldn’t tell a difference.

Also, I believe you can have 4GB of ram with XP 32 bit. The amount of usable RAM is dependent on the hardware devices you have in your system.

32 bit OS (like WinXP) are capable of addressing all 4 GBs of RAM, however, some is set aside for hardware devices (PCI-E, PCI, etc.) which is why you will see Windows reporting something less than 4GBs.

Usually you will see somewhere between 2.75GB and 3.5GB available.

With 4 sticks will keep your system operating in dual channel mode, where as 3 x 1GB will not. So, put in the 4 x 1GB and enjoy.

Edited April 17, 200818 yr by Smiley357

I gather that a 32-bit OS (i.e. what I'm running now) will only allocate a maximum of 2GB to any one process a ta time, whilst a 64-bit OS can allocate more (in application space).

You are sort of correct, but in terms of Virtual Memory. Don't confuse this with physical RAM.

I further gather that a 32-bit Windows OS only has a maximum of 2GB in kernel space to allocate between all running programs. Can one assume that a 64-bit OS would, again, be able to use more?

Again, correct but replace "kernel space" with "virtual memory". See previous comment.

See this thread and the threads linked within it for more information:

http://www.msfn.org/board/32bit-Windows-no...RAM-t97580.html

Edited April 17, 200818 yr by nmX.Memnoch